Abstract

Novel psychoactive substances (NPS), which emerged at the beginning of the 2000s have become a serious and internationally complex situation. These emerging drugs are mostly synthetic and analog derivatives of existing controlled drugs. They are sold ubiquitously not only on traditional markets but also through the Deep Web/Dark Web, where their regulation is even harder. The most important groups comprise synthetic cannabimimetics, cathinones and psychodysleptic phenethylamines. The variety and evolution of this kind of substances has given rise to a continuous analytic challenge for their detection and quantification in seizures and biological fluids. Instrumental chromatographic techniques such as  HPLC-DAD, GC-MS, LC-MS, UPLC-MS-MS have provided considerable advantages, although there is still a paucity of standards available and lack of awareness of the metabolites that might be generated in vivo. In this review we will provide an overview of each group of substances and their toxicity, as well as of the analytical methods used in seizures and biological matrices.